A filing on Wednesday in a high-stakes legal battle between Samsung and Apple revealed that a "pinch-to-zoom" patent central to the case has been deemed invalid.
The patent was a centrepiece of a trial that ended in August with a jury ordering Samsung to pay Apple $1.05-billion in damages for illegally copying iPhone and iPad features for its flagship Galaxy S smartphones.
Samsung provided US District Judge Lucy Koh a copy of a US Patent and Trademark Office preliminary determination that, upon review, the Apple pinch-to-zoom technology wasn't original enough to merit a patent.
Samsung hoped the filing would bolster its argument for a new trial or to have the damages award slashed.
Since the verdict, US patent officials tentatively invalidated an Apple patent on technology that gives a "rubber-band" springing effect when a finger tugs at the edge of a touch-screen smartphone. That patent was also at issue at trial.
Koh on Monday denied Apple's request to ban a set of Samsung smartphones from the US market based on the jury's finding that the South Korean firm was guilty of infringing on six of the Cupertino, California-company's patents.
Even though Apple was victorious in the patent case, the iPhone and iPad maker failed to prove that the technology at issue was the driving factor in people's buying decisions, Koh reasoned in the ruling.
Samsung - the world's top mobile and smartphone maker - has appealed the verdict.